Preheat oven to 200C (fan forced). Line a 40cm x 27cm baking tray with a large sheet of baking paper overlapping the sides.

Combine chicken and 1/3 cup of Butter Chicken Paste in a bowl until lightly coated in sauce. Reserve remaining sauce or freeze for another use.

Scatter 3/4 of the onion over the base of prepared pan in a 33cm x 20cm rectangle. Top with chicken and peas. Spread spinach over the top, keeping within rectangle.

Overlap pastry sheets by 7cm and press together to join. Trim 2cm off each end so pastry is the same length as prepared tray. Lift pastry over filling on tray and press down around filling. Pinch edges of pastry to form a decorative edge.

Make slashes across the top of pastry with the tip of a knife without going all the way through. Brush all over with egg. Bake for 25 minutes or until puffed and golden.

Meanwhile; combine yoghurt, juice and 1 tablespoon water in a bowl.

Combine remaining onion, carrot, cucumber and coriander in a bowl. Set aside.

Place a board on top of oven tray and turn over to invert. Peel away paper and cut into pieces. Serve drizzled with yoghurt mixture, topped with salad.